Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are d...Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.展开更多
In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optic...In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.展开更多
In this article, based on the analysis of the current environmental situation in Russia and other countries, as well as of the problem of recycling plastic waste in the Russian Federation （RF）, the authors clearly s...In this article, based on the analysis of the current environmental situation in Russia and other countries, as well as of the problem of recycling plastic waste in the Russian Federation （RF）, the authors clearly show the effectiveness of investments in the processing of polymer debris on the example of polyethylene terephthalate （PET） waste （granulates, flakes）. In the frame of case study of social and environmental investment project on creating enterprise that will engage in collection, recycling, and sale of the consumer PET packaging in Russia, the authors demonstrate the economic feasibility of the creation of such kind of enterprises taking into account market conditions and the features of the existing system of taxation in Russia. The realization of the project will also help in solving environmental and social problems of large cities, in particular, will create more jobs （in terms of 6% of unemployment rate in the country）. The study also identifies the main obstacles in the way of waste recycling in Russia, and the recommendations for improvement of normative base of the industry are given.展开更多
Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (...Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the展开更多
Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials ...Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.展开更多
The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact ang...The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.展开更多
The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies ha...The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate （PET）, because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450℃ for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron （iron nuggets） were reduction at 1450℃ for 10 min using composite pellets containing 60% PET and 40% coke.展开更多
Irradiation cross-linking of flame-retardant polyethylene terephthalate( FR-PET) fabric with the presence of trimethylolpropane triacrylate( TMPTA) was studied. Thermal gravimetric( TG) analysis,differential scanning ...Irradiation cross-linking of flame-retardant polyethylene terephthalate( FR-PET) fabric with the presence of trimethylolpropane triacrylate( TMPTA) was studied. Thermal gravimetric( TG) analysis,differential scanning calorimetry( DSC) and scanning electron microscopy( SEM) were used to analyze the effects of irradiation crosslinking on structure and property of FR-PET fabric with TMPTA. The cross-linking was promoted by the introduced sensitizer. The gel content was 5.94% at the lower dose of 90 kGy and it arrived at the highest level of 13.01% with the increased doses. There were no melt drips of FR-PET fabric after irradiation cross-linking while the flame retardance disappeared at the time of combustion. The melting temperature of irradiated fabric decreased and TG analysis showed that the onset temperature of degradation of FR-PET fabric and the amount of nonvolatile residue at 800℃ increased as the irradiation dosage increased,but it changed a little compared with the pure FR-PFT fabric. SEM photographs showed that the residue char of irradiated PET fabrics after vertical test remained the intrinsic crossed structure,and the enlarged graph showed that the char was uniformly distributed and it was tight honeycombs structure.展开更多
Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resi...Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resin was isothermal crystallized at temperature of 140,170,200 and 230 ℃ for 5 hours,the crystallinity of the resin was 25.7%,29.5%,33.9% and 40.6%,respectively,then the resin with different crystallinity was hydrolyzed under microwave irriadition. Under the same conditions of hydrolytic depolymerization, the degree of PET depolymerization decreased from 72.8% to 69.34% with the increase of crystallinity of PET resin,the rate of depolymerization varied little with the increasing of crystallinity of PET,this indicated that the crystallinity of PET has little effect on the hydrolytic depolymerization.The crystallinity of PET was increased during the temperature elevating process of the hydrolytic depolymerization.Investigation by DSC proved that the crystallinity of PET resin increased notability during the same temperature elevating process as the hydrolyzed depolymerization.According to the theory that depolymerization was firstly proceed in the amorphous phase,the crystallinity should increase during the reaction.However,the crystallinity of PET residue was decreased during all the reaction process,this indicates that the hydrolysis did not preferentially occur in the amorphous phase.展开更多
基金The Ministry of Natural Resources and Environment(No.TNMT.2022.05.04).
文摘Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.
文摘In this work,polyethylene terephthalate(PET) fibers were continuously treated by atmospheric dielectric barrier discharge(DBD) in Ar mixed O2 plasma,and the discharge was characterized by electrical function and optical diagnostics.It is found that the interfacial adhesion strength between treated PET fiber and resorcinol formaldehyde latex(RFL)(little)-rubber was improved(about 50%) by the measurement of interfacial shear strength(IFSS) and peel test.The wettability was improved rapidly in the initial treatment time.It is considered that oxidation chemical reaction as the major role of PET fiber surface modification is ahead of the physical etching effect.The high density of atomic oxygen in the plasma by optical emission spectroscopy supports the purpose.According to the scanning electron micrograph(SEM) image in the work,the longer treatment time obviously caused physical etching effect,which shall be less responsible for the improvement of the wettability.
文摘In this article, based on the analysis of the current environmental situation in Russia and other countries, as well as of the problem of recycling plastic waste in the Russian Federation （RF）, the authors clearly show the effectiveness of investments in the processing of polymer debris on the example of polyethylene terephthalate （PET） waste （granulates, flakes）. In the frame of case study of social and environmental investment project on creating enterprise that will engage in collection, recycling, and sale of the consumer PET packaging in Russia, the authors demonstrate the economic feasibility of the creation of such kind of enterprises taking into account market conditions and the features of the existing system of taxation in Russia. The realization of the project will also help in solving environmental and social problems of large cities, in particular, will create more jobs （in terms of 6% of unemployment rate in the country）. The study also identifies the main obstacles in the way of waste recycling in Russia, and the recommendations for improvement of normative base of the industry are given.
文摘Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the
基金Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China(No.2005-383)
文摘Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.
文摘The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.
基金financially supported by Yildiz Technical University Scientific Research Projects Coordination Department (No. 2011-07-02-KAP02)
文摘The increasing consumption of plastics inevitably results in increasing amounts of waste plastics. Because of their long degradation periods, these wastes negatively affect the natural environment. Numerous studies have been conducted to recycle and eliminate waste plastics. The potential for recycling waste plastics in the iron and steel industry has been underestimated; the high C and H contents of plastics may make them suitable as alternative reductants in the reduction process of iron ore. This study aims to substitute plastic wastes for coal in reduction melting process and to investigate their performance during reduction at high temperature. We used a common type of waste plastic, polyethylene terephthalate （PET）, because of its high carbon and hydrogen contents. Composite pellets containing PET wastes, coke, and magnetite iron ore were reduced at selected temperatures of 1400 and 1450℃ for reduction time from 2 to 10 min to investigate the reduction melting behavior of these pellets. The results showed that an increased temperature and reduction time increased the reduction ratio of the pellets. The optimum experimental conditions for obtaining metallic iron （iron nuggets） were reduction at 1450℃ for 10 min using composite pellets containing 60% PET and 40% coke.
基金National Natural Science Foundations of China(Nos.51403112,51273097,51306095)Qingdao Postdoctoral Application Research Funded Project,China(No.2015132)Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province,China
文摘Irradiation cross-linking of flame-retardant polyethylene terephthalate( FR-PET) fabric with the presence of trimethylolpropane triacrylate( TMPTA) was studied. Thermal gravimetric( TG) analysis,differential scanning calorimetry( DSC) and scanning electron microscopy( SEM) were used to analyze the effects of irradiation crosslinking on structure and property of FR-PET fabric with TMPTA. The cross-linking was promoted by the introduced sensitizer. The gel content was 5.94% at the lower dose of 90 kGy and it arrived at the highest level of 13.01% with the increased doses. There were no melt drips of FR-PET fabric after irradiation cross-linking while the flame retardance disappeared at the time of combustion. The melting temperature of irradiated fabric decreased and TG analysis showed that the onset temperature of degradation of FR-PET fabric and the amount of nonvolatile residue at 800℃ increased as the irradiation dosage increased,but it changed a little compared with the pure FR-PFT fabric. SEM photographs showed that the residue char of irradiated PET fabrics after vertical test remained the intrinsic crossed structure,and the enlarged graph showed that the char was uniformly distributed and it was tight honeycombs structure.
文摘Polyethylene terephthalate(PET) resin was hydrolyzed to terephthalate acid(TPA) and ethylene glycol(EG) under microwave irradiation.The effects of crystallinity on the depolymerization of PET was investigated.PET resin was isothermal crystallized at temperature of 140,170,200 and 230 ℃ for 5 hours,the crystallinity of the resin was 25.7%,29.5%,33.9% and 40.6%,respectively,then the resin with different crystallinity was hydrolyzed under microwave irriadition. Under the same conditions of hydrolytic depolymerization, the degree of PET depolymerization decreased from 72.8% to 69.34% with the increase of crystallinity of PET resin,the rate of depolymerization varied little with the increasing of crystallinity of PET,this indicated that the crystallinity of PET has little effect on the hydrolytic depolymerization.The crystallinity of PET was increased during the temperature elevating process of the hydrolytic depolymerization.Investigation by DSC proved that the crystallinity of PET resin increased notability during the same temperature elevating process as the hydrolyzed depolymerization.According to the theory that depolymerization was firstly proceed in the amorphous phase,the crystallinity should increase during the reaction.However,the crystallinity of PET residue was decreased during all the reaction process,this indicates that the hydrolysis did not preferentially occur in the amorphous phase.
